Gun



1935. G. M. MOCANN ET AL 1,986,37

Filed May 10, 1955 Inventura Geurge M-McEann Thmmaa K Vincant A TTORNEY Patented Jan. 8, 1935 masses;

George M. McOann, New Castle,

Del., and

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

This invention relates to a gun, and more particularly it has reference to a gun in which a radial play space provided between a loose liner or inner tube and an outer tube is taken up in firing and is restorable after firing.

Where the loosely fitted inner tube is inserted through the breech end of the outer tube some means must be provided for holding the inner tube against rearward movement especially when the gun is in position of elevation. Heretofore it has been the practice to accomplish this purpose by means of rings or cross-pmsmounted in the breech end of the outer tube butthis method of holding presents disadvantages from the standpoint of manufacture and assembly and. disassembly. v

The purposeof this invention is to provide holding means for the inner tube which may be conveniently associated with the muzzle ends ofthe inner and outer tubes and which will allow free longitudinal expansion and contraction of the inner tube. i

To these and other ends, the invention consists in the construction, arrangement and combination of elements described hereinafter and pointed out in the claims forming a part of this specification. v I v A practical. embodiment of the invention is illustrated in the accompanying drawing, where- Fig. 1 is a longitudinal sectional view of a gun having a removable inner tube held in the improved manner.

Fig. 2 is an enlarged longitudinal sectional view through the muzzle showing the holding means, and i Fig. 3 is a detail sectional view on the line 8-3 of Fig. 2.

There is shown a gun consisting of an outer tube 5 and an inner tube 6 freely insertable in the outer tube from therear. The outer diameter of the inner tube 6 is less than the inner diameter of the outer tube 5 to establish a radial play space '7 between theftubes. In this type of gun the powder pressure acts in firing to dilate the inner tube into contact with the outer tube but the play space is restored when the pressure is no longer present. 1

Since the innertube 6 is loosely mounted in the outer tube 5 and would be free to move rearwardly 55 upon inclination of the gun there is provided a holding means consisting of a spring 8 seated on the front face of the outer tube and acting on the inner tube. In the preferred embodiment illustrated in the drawing, the muzzle end 9 of the inner tube projects beyond the outer tube and 5 has a collar 10 threadedly mountedon its extremityto form a seat for the spring 8. The spring 8 embraces the projecting end 9 of the inner tube. A sleeve 11 integral with the collar extends rearwardly andslidably embraces the front end of 10 the outer tube. The sleeve forms a closure for the space occupied by the spring as seen in Fig. 1. Thecollar is held in place by means of a locking screw 12 and is provided with apertures 13 for receiving a spanner wrench. 15

The rear end of the innertube is formed with one or more collars, two being shown and designated l4 and 15. These collars abut against annular shoulders 16 and 1? in the outer tube and prevent forward movement of the inner tube rela- 2o tive to the outer tube. Opposite keys 18-18 are provided on the inner tube between the shoulders 16and 17 of the outer tube and by engaging in key-ways '19 in the outer tube hold the inner tube against rotational movement relative to the 25 outer tube.

When it is desired to remove the inner tube it is only necessary to remove the collar 10 and the inner tube is free to be withdrawn rearwardly. When a new inner tube is inserted the only opera- 30 tion required is to apply the spring and collar.

The spring 8 is of sufilcient capacity to hold the inner tube in its forward position and will not interfere with free longitudinal expansion and contraction of the inner tube.

We claim:

l. A gun comprising an outer tube, an inner tube insertable in the outer tube through the breech end thereof and projecting from the front end thereof, means for limiting forward move 40 ment of the inner tube relative to the outer tube,

a collar threadedly mounted on the projecting end of the inner tube, a spring embracing the projecting end and confined between the collar and the front face of the outer tube, and a sleeve 45 extending rearwardly from the collar and slidably embracing the outer tube.

2. A gun comprising an outer tube, an inner tube insertable in the outer tube and projecting from the front end thereof, means for limiting 50 forward movement of the inner tube relative to the outer tube, a collar threadedly mounted on p the projecting end of the inner tube, a spring embracing the projecting end and confined between the collar and the front face of the outer tube.

and a sleeve extending rearwardly from the collar and slidably embracing the outer tube.

3. A gun comprising an outer tube, a removable inner tube within the outer tube and projecting from the front end thereof, means for limiting forward movement of the .inner tube relative to the outer tube; a removable collar on the projecting end of the inner tube, a spring confined between the collar and the front face of the outer;

tube, and a sleeve extending rearwardly from the collar and slidably embracing the outer tube." 

